
*** Build Information ***
CHDK for m3 fw:121a PID:12953
build:1.7.0-6343_ALPHA date:Sun, 21 Sep 2025 04:57:22 +0200

*** Camera specific notes ***
EOS M3 notes

CHDK is a hack, use at your own risk!

CHDK support for interchangeable lens cameras is incomplete.

Many features and combinations of Canon settings have not been tested.
Builds are available for firmware 101A, 120F and 121A.

Please post bug reports and patches in the porting thread
https://chdk.setepontos.com/index.php?topic=12542.0

Keys
- M-Fn is the default alt button, and is assigned to PRINT in CHDK code.
- Video and Info (Display) may also be used for alt
- Info assigned to Display for CHDK keyboard input and script.
- AE Lock and AF Adjust are assigned to zoom out and zoom in
  respectively for CHDK keyboard input and script. They do not control the lens zoom.

Notes

- Video bitrate can be adjusted (CBR, VBR). Maximum possible video bitrate is approx. 41000 kbit/s

- Clean overlay is possible for HDMI output purposes: See "Video Parameters" -> "Clear Canon overlays"
  "Rec": Canon overlay is removed upon entering shooting (aka rec) mode
  "MviRec": Canon overlay is removed when recording video
  CHDK overlay needs to be removed separately, in the "CHDK Settings" menu.
  For more info, visit https://chdk.setepontos.com/index.php?topic=13489

- This camera can switch on itself after a user-initiated delay. This feature can be used from a user-written Lua script.
  For more details and the script, see https://chdk.setepontos.com/index.php?topic=12542.msg137151#msg137151

- M3 can boot CHDK from cards formatted FAT32 or FAT16, but not exFAT. Cards
larger than 32 GB generally default to exFAT and must either be re-formatted
FAT32 or partitioned with a FAT16 boot partition to enable CHDK autoboot.
Using an exFAT partition for images is reported to give better performance
with large cards.

Issues:

- CHDK overlay drawing is slow
- many GUI modules don't respect screen resolution
- Edge overlay does not erase properly when shown live
- Zebra "Draw Over Zebra" and Restore options are non-functional
- Some games don't draw correctly
- movie features are not supported
- Only simple_movie_status is implemented, so features or scripts that rely on
direct access to the movie_status variable do not work
- Tv overrides do not work in some cases
- mode map is incomplete, getting / setting mode from script or PTP may fail

TESTED:

PTP play/rec switch
raw and remote hooks (in normal still shooting modes, broken some special modes)
USB remote - plug test / remote hook only
CHDK raw / DNG (in P, M, Tv, Av modes. AUTO not well tested, many others broken)
 - Attempting to use CHDK DNG in modes other than P, M, Tv, Av is not recommended
PTP remote shoot with JPEG, CHDK DNG and Canon raw (with chdkptp r964 or later)
 - May fail in special scene modes (not extensively tested)
Motion detection - preliminary
PTP live view - preliminary, requires client with live view protocol 2.2 (chdkptp r723 or later)
Multipartition boot with FAT16 + exFAT

NOT IMPLEMENTED:

dark frame control
reboot with firmware update file
script hard shutdown (shut_down(1))
booting with .fi2, camera crashes
subject distance (focus) override
Zoom control with set_zoom (lenses don't have software zoom control)
